The invention relates to window coverings. More particularly, it provides an easily installable blind for use with a conventional window.
Window blinds are a popular window treatment mounted to a window frame to provide added color to a room decorating scheme and to control the amount of light entering through the window panes. As shown in FIG. 1, a typical conventional window installed in a wall opening has a window frame 11, with a sill 13, opposed jambs (not shown), and a head member 15. The window frame 11 defines a window opening 17 which is closed by one or more panes 19 of glass set in a sash 21. The sash 21 is moveable from an open to a closed position allowing air to pass through the window opening 17.
The window frame 11 is typically adapted to form an insert receptacle 39 for receiving a screen insert 37. The screen insert prevents insects from passing through the window opening 17. Stops 41 or grooves formed in the frame 11 define the insert receptacle 39 slightly larger than the insert perimeter for easy insert 37 insertion and removal.
A blind 23 mounted to the window frame 11 controls light passing through the window opening 17. Typically, the blind 23 has a headrail 25 with a blind control mechanism 9 which angularly controls the tilt angle of slats 27 suspended from the headrail 25 in front of the window opening 17. A lift mechanism in the control mechanism 9 raises and lowers the slats 27. Light passing through the window opening 17 is controlled by lowering the slats 27 and tilting them to block the light.
The prior art blind 23, as shown in FIG. 1, is installed by mounting retaining clips 29 to the window frame 11, or trim attached thereto, and then slipping the blind headrail 25 into the clips 29. Mounting the clips 29 to the frame 11 requires measuring the length of the blind headrail 25 and transferring the measurements to the window frame 11. A drill is required to drill holes in the window frame 11 for screws 31 which secure the clips 29 to the frame 11. The clips 29 must be held in position while the screws 31 are threadably inserted into the frame 11 through the clip 29.
The clips 29 are generally located near the head member 15 and are typically in each upper corner of the window frame 11 making drilling and screwing difficult and awkward. Additionally, if the measurements are incorrect and the headrail 25 is too long or too short for the clip positions, one or more of the clips 29 must be unscrewed from the frame 11 and the process repeated, leaving unsightly holes in the window frame 11 as evidence of the first failed attempt to mount the blind 23.
Prior art blinds 23 also may interfere with existing window controls. The slats 27 or a bottom rail 33 of the blind 23 mounted to casement-type window often interfere with a window crank 35 extending from the window frame 11. The crank 35 operates a sash mechanism which opens and closes the sash 21 in the casement-type window. Slat interference with the crank 35 makes operating the sash mechanism difficult.
The prior art blind 23 may also impair access to the screen insert 37 disposed in the insert receptacle 39. Even when the downwardly depending slats 27 are fully retracted, they may block a portion of the window opening 17 and interfere with the removal or insertion of the screen insert 37. This makes cleaning the window panes 19 difficult.
One method which solves the installation and interference problems is to provide a window having a factory installed blind disposed between two panes of glass, such as described in U.S. Pat. No. 4,884,613. This particular method increases the cost of the window and requires complete replacement of existing windows if a blind is desired.